iProXProteomicsSoonheng TanHomo Sapienshttp://www.iprox.org/page/project.html?id=IPX0011486000christan@sustech.edu.cnSouthern University of Science and TechnologyiProXProteolysis-targeting chimeras (PROTACs) present a potentially effective strategy against various diseases via selective proteolysis. How to increase the efficacy of PROTACs remains challenging. Here, we explore the necessity of the linker, which has been deemed as an integral part of heterobifunctional PROTACs. Adopting single amino acid-based degradation signals, we find that the linker is not a required feature of the PROTACs. Notably, the linker-free PROTAC, Pro-BA, exhibits superior efficacy over its linker-bearing counterparts in degrading EML4-ALK and inhibiting lung cancer cell growth, as Pro-BA induces a stronger interaction between the target and the E3 ubiquitin ligase. Pro-BA is a water-soluble, orally administered degrader that significantly inhibits the tumor growth in a xenograft mouse model. The broad applicability of this linker-free PROTAC strategy is further validated through the development of BCR-ABL degrader. Our study introduces a design paradigm for PROTACs, potentially facilitating the advancement of more efficient therapeutic degraders.Linker-free PROTACs efficiently induce the degradation of oncoproteins.Zhang Jianchao J, Chen Congli C, Chen Xiao X, Liao Kefan K, Li Fengming F, Song Xiaoxiao X, Liu Chaowei C, Su Ming-Yuan MY, Sun Huiyong H, Hou Tingjun T, Tan Chris Soon Heng CSH, Fang Lijing L, Rao Hai HfalseInvestigating the off-target effects of Pro-BA using label-free and TMTpro quantitative proteomicsNevertheless, in-depth characterization of the proteome could reveal unknown off-targets of Pro-BA. To address this issue, we repeated the same experiment but extended MS analysis time to 2 hours in this revision, which will be elaborated in the next point. Nonetheless, the computed p-value of ALK p-value is less than 0.05, with and without FDR correction, with the new dataset.Tue Mar 25 00:00:00 GMT 2025PXD062245960640410168